Tyres with spikes are pretty much mandatory if you're using a touring bike (mountain bikes with balloon tyres may cope fairly well with snow, I guess) on snow a

Tyres with spikes are pretty much mandatory if you're using a touring bike (mountain bikes with balloon tyres may cope fairly well with snow, I guess) on snow and ice. IMHO they're not optional. And you don't tend to get used to slipping on ice. (Edit: I'm in Germany; we tend to get snow and ice in winter and the cycle paths are not always cleared immediately.)